The ability to automatically monitor the wound healing process would reduce the workload of professionals, provide standardization, reduce costs, and improve the quality of care for patients. Here we propose an automatic monitoring system for leg ulcers based on case-based reasoning. We focus on the first stage of the monitoring process in this work, that of tissue classification and examine a number of different feature extraction techniques based on texture and Red, Green, and Blue histograms. Results clearly show a case-based approach to be ideal for this type of task.